This invention relates to orthopaedic hinged braces for use with human body bone joints by being mounted on the exterior of the skin surface surrounding the joint.
When a patient is being treated for an injury, it is often times desirable to limit the patient's range of bone joint pivoting in the initial stages of healing, so that at first the range of movement is limited, but so that as time passes and as healing progresses, a greater range of movement is allowed to prevent atrophy and to allow a controlled rate of the patient working himself back in condition. Furthermore, in some situations only a limited range of movement may be desired for a previously injured body part.
In the prior art, braces have been used to help support knees. Such braces have an upper and a lower brace extension pivotally connected. Some of these knee braces have had ways to restrict pivotal movement of the restrictions. In one prior art device, this has been by a metal wire with its two ends each secured by a screw nut to points on each of the two extensions, so that the wire tension limits the extension of the knee when the brace is on, but does not limit flexion of the knee. The screws can be loosened to detach the connection of the wire ends to the brace extensions to allow the length of the wire between the two nuts to be shortened or lenghtened to thus increase or decrease the amount of extension permitted. Such a device has a number of drawbacks. For one, the wire can get caught on other objects and trip the user. This is especially a problem when the brace is flexed quite a bit, and the wire is slack and loops out from the brace. Also the fastening points of the wire are away from the pivotal connection of the braces. The wire is subject to breaking under tension, and also is subject to contact from other objects which can gash it and weaken it to thus expedite breaking, or in fact cut the wire. The wire furthermore can limit only flexion.
In another device used on the knee there are top and bottom brace extensions pivotally connected by a screw. In between each of the extension ends where the pivotal connection is located, there is a circular plate with a center hole which has on one side a plurality of V grooves radiating out from its center and on the other side has a lug projecting outwardly therefrom. The inner end of one of the brace extensions likewise has, on one side, V grooves radiating out from the point of pivotal connection of that extension, which grooves mesh with the V grooves of the intermediate plate to lock movement of the plate relative to the brace extension. The other brace extension has on the inside of its inner end four recesses of arcuate shape, each of a different arcuate length, and each of which can receive the lug on the intermediate plate. The two extensions and the intermediate plate are secured by a large screw and nut arrangement, as well as with a sleeve that provides centering of the members. The first extension can thus pivot relative to the second extension with the range of movement dependent upon which of the arcuate recesses within which the lug is placed. In one recess the pivotal range is from 0 degree-70 degrees, in another recess the range is 0 degree-10 degrees, in another 0 degree-40 degrees, and in the fourth position the position of the brace extensions are fixed relative to each other and no pivoting occurs.
This type of device has disadvantage in that to readjust the pivoting range, the brace should be taken off the user, and the pivot screw connecting the members removed to detach the first brace extension from the second extension. The intermediate plate must be disengaged from the extension having the arcuate recesses, and rotated so the lug can be inserted in another selected recess. During all this, the hand must be used to hold the screw and sleeve to prevent them from falling on the floor. After this adjusting has occurred, the other brace extension can again be mounted to the pivot screw and the nut attached to hold the members together. This is an awkward procedure in which the members can fall on the floor and be lost or broken and furthermore takes excessive time even after the brace is detached from the body. The device comprises a number of parts, and it provides only three ranges of actual pivot movement. The fact that the recesses are located in a circular arrangement about the pivot point necessarily limits the possible ranges of pivoting that can be provided.
In the prior art there have also been plastic rods which have been mounted to casts on the body which allow some flexing simply because they were not completely rigid. However, with such flexible plastic brace extensions there is no way to adjust the range of pivotal movement and the range of movement is simply dependent on the degree of rigidity of the rod.